The invention relates to a latch for a motor vehicle.
A latch for a motor vehicle comprises a locking mechanism with a rotatably mounted catch accommodating a locking bolt, also referred to as latch holder. The locking mechanism also contains a pawl that can engage the catch in order to retain the locking bolt.
The catch of a motor vehicle latch usually contains a fork-like inlet slot (also referred to as inlet section) formed by a load arm and a collecting arm, which is entered by a locking bolt of a motor vehicle door or flap, such as a bonnet or boot lid when the door or flap is shut. The locking bolt or the latch holder then turns the catch from an opening position to a closed position until the pawl locks the catch. This position is referred to a detent position. The locking bolt can then no longer leave the inlet slot of the catch.
A latch can also contain a lock lever that can block the pawl in its detent position. The lock lever must be pivoted or turned out of its locking position so that the pawl can leave its detent position for opening the locking mechanism.
Latches exist in which the catch can introduce an opening moment into the pawl, if it is in its detent position. A lock lever is required for such a latch in order to lock the locking mechanism into place. Such latches can be opened with little force.
Motor vehicle latches exist, that feature two detent positions, a pre-ratchet position and a main ratchet position. The pre-ratchet position serves to retain the door or flap if it has not reached the main ratchet position during closing. If the catch is turned further starting from the pre-ratchet position, it eventually reaches the main ratchet position.
A latch generally contains a release lever required to open a locking mechanism and to release it. Such a release lever is typically connected to the handle of a door or of a flap. Upon actuation of the handle, the release lever is actuated and pivoted in order to release the locking mechanism and thus open the latch.
In the event of a crash, the handle can be accidentally activated, causing the locking mechanism to be opened. It should be ensured that such a latch can not accidentally open in such a situation.
In order to ensure that a latch cannot accidentally open in the event of a crash, printed matter EP 1518983A2 provides a latch with a locking mechanism, containing at least one actuating lever for triggering or opening the locking mechanisms, i.e. a release lever. The latch also contains a lock lever locking the actuating lever in case of a specified acceleration of the vehicle.
During a crash, particularly high accelerations are generated compared to the usual opening. If the lock lever blocks only during high vehicle accelerations, as experienced in the event of a crash, unintentional opening of the locking mechanisms in the event of a crash can be prevented. In case of a usual actuation of the door handle, the actuating lever is not blocked as no high acceleration is applied, allowing opening of the latch.
In the event of a crash, a rebound effect also referred to as bouncing can follow the excessive acceleration forces experienced during a crash. A delayed or repeated bouncing, in particularly coupled with changing acceleration forces and directions can cause a failure of the locking device during high acceleration, aiming to prevent accidental opening of the latch in the event of a crash.